Magnetic core assembly



Dec. 20, 1960 T. LA PATKA ET AL 2,965,864

MAGNETIC com ASSEMBLY Filed OO'L. 26, 1956 2 Sheets-Sheet 1 IN V EN TORS LAWRENCE T. LA PATKA WILL AIVI P. SCHMIDT BY AGENT Dec. 20, 1960 T. LA PATKA ETAL 2,965,864

MAGNETIC CORE ASSEMBLY Filed oct. 26, 195e 2 sheets-sheet 2 IN VEN TORS LAWRENCE "I LAPATKA Y 1 WILLIAM P SCHMIDT AGENT United States Patent O MAGNETIC conn ASSEMBLY Lawrence T. La Patka, Collingswood, NJ., and William P. Schmidt, Bethayers, Pa., assignors to Burroughs Corporation, Detroit, Mich., a corporation of Michigan Filed Oct. 26, 1956, Ser. No. 618,648

6 Claims. (Cl. 336-92) The present invention relates to toroidal magnetic cores and more particularly to unit assemblies of vsuch core structures.

In magnetic core assemblies as heretofore fabricated, cost and time factors have presented problems seriously handicapping their production on an economical basis and thereby necessitating undesirably high prices for equipment requiring such units. Time factor problems are primarily caused by the required hand manipulation of the exceptionally small parts used in their manufacture and the tedious interconnection of elements to assemble operative units. High cost naturally follows from the multiplication of man hours necessary for production, a factor heretofore found to be an obstacle to commercial marketing.

An object of the present invention is to provide a magnetic core assembly wherein the foregoing problems have been solved.

Another object is to provide a core assembly involving a minimum of parts which can be quickly and easily put together to form a compact core unit, effectively shielded from associated circuits, such as those used in electrical computer systems.

Another object is to provide a core asembly wherein a magnetic toroidal wound core is supported between lead wires of input and output circuits, and in a manner shielded against local interference.

In carrying out the object of the invention, an exemplary assembly would include a magnetic core having windings connected to lead wire terminals supported by insulating elements extending into and supporting the core. lf desired, the assembly may be housed within an insulating cylinder telescoped within a metal shell having its ends sealed by a suitable material through which the lead wires project for circuit connection.

Various other objects, advantageous and meritorious features of the invention will become more fully apparent from the following specification, appended claims and accompanying drawings, wherein:

Figure 1 is an exploded perspective view of one form of the invention;

Figure 2 is a transverse sectional view of the unit of Figure l, when assembled;

Figure 3 is an exploded perspective view of a modiiied form of the invention, now forming the subject matter of the co-pending divisional application in the same names and same title as the present invention and bearing Serial No. 461 (1960 series) filed December 21, 1959, and assigned to the same assignee as the present invention;

Figure 4 is a sectional View similar to Figure 2, but of the modified form;

Figure 5 is an exploded perspective view of another modification of the invention;

Figure 6 is a perspective view of the modiication shown in Figure 5 showing it mounted on a printed cir cuit panel;

Figure 7 is a transverse sectional view of the modification shown in Figures 5 and 6; and

Figures 8 and 9 are plan views illustrating how certain elements of the invention may be modied.

Referring to Figures 1 and 2 of the drawings, the pre ferred form of the invention is shown comprising a magnetic core 10 of the solid toroidal or ring type having, in the present instance, two windings 11 and 12 wound thereon, the respective ends of which are bonded to two pairs of conducting wires, rods, or pigtails 13, 14 and 15, 16, as indicated in Figure 2 by the reference characters 17, 1S, 19 and 20. The pair of wires 13 and 14 function as one part of an electrical circuit and the pair of wires 15 and 16 serve as a part of another circuit, each pair being suitably supported in insulated condition upon associated structure such as a panel, base or other mounting, not shown. One pair can be the input of a signal transmitted to its winding on the core and the other pair can be the output from its signal induced winding, for example, a read-out or memory storage of electrical computers.

In order to mount the extended core winding wires in non-conducting relation and for quick inexpensive assembly as a unit, wires 13 and 14 are attached respectively to opposite sides of the cross-head 21 of one of a pair of similar T-shaped flat planar retainers 22 and 22 of insulating and non-magnetic material. The Shanks 23 and 23' of each of the retainers is formed with a pair of medially disposed and aligned slots 24 and 25 the latter of which terminates just short of the head 21 of the retainer. The width of the slots is substantially equal to the thickness of the retainer material. Slot 24 divides the outer end of shank 23 into somewhat iiexible ngers 26 and 27 having hooked end portions 28 and 29 formed with tapered edges 30 and 31 respectively to guide the fingers 26' and 27 of the correspondingly shaped member 22 into engagement therewith, which engagement is effected with the plane of the retainers angularly displaced relative to each other with the angle of displacement preferably Wires 15 and 16 are similarly attached to opposite sides of the cross-head 21 of the second retainer 22. When fully engaged with each other the hooked end portions 28 and 29 of each retainer is engaged in slot 25 of the other.

Thus it is seen that the bifurcated shanks 23 and 23 permit the retainers to be interlocked with the respective retainer planes at right angles to each other. Furthermore, it should be noted that the width of each retainer shank is dimensioned to fit relatively snugly into the bore of the magnetic core 10 which is to be mounted. Also the length of the interlocked retainer Shanks is such as to comfortably receive the thickness of the selected core between the two angularly disposed T-heads 21 and 21. Preferably there may be, as shown in Figure 2, a slight clearance between the core and the heads for more ready bonding of the core winding ends to the pairs of lead wires 13-14, and 15-16.

It should be understood that the assembly as described thus far, forms a complete usable core assembly and it is contemplated that it will be so used where a housing is not considered necessary. A feature of the presently illustrated assembly, however, is that the two cross-heads of the retainers are equal in length but preferably greater than the diameter of the core which is mounted between them, thus to provide the necessary spacing for telescopically inserting the assembly within a housing 32. The housing may conveniently comprise a cylinder 33 of insulating, non-magnetic material having a length suicient to encircle the mounted core assembly while leaving the pairs of` lead wires projecting from its opposite ends. When so placed an outer cylindrical shell 34 of metal or other sufciently rigid material is slipped over cylinder 33 with its ends projecting beyond both ends of cylinder 33, thus to provide seats 35 at both ends of the pressed conditionis ysnapped intothe recess 317r andgal-V lowedgto expand againstshell 34; thus toretaintheclo- Sure.:disksSeated against the endsoficylinder 3.3.. Leads 13tlarjgnlgh,16 pass through spaced apertures 39,-;in the` dislgsjand maybe sealed ,thereto in any suitablegrnanner.' The1 rings are now soldered in place lthereby to encapsulatev and hold; thev elements Aof the .assembly against displacement. If-desired, ring 38 maybe eliminated and recess,37 lled with solder.

In the` modified form of the invention shown in Figures 3 vand 4,- and-forrning the. subjectmatter of the aboveidentified divisional application, the. core sub-,assembly is adaptedto be telescopically encased within a housing similar to thatshown in Figures 1 andl 2, In thisform atube 4t). of insulating, non-magnetic material, such` as nylon, is lpositioned through the bore of the core 10, with itsends projecting at opposite sidesof the` toroid to support the inner ends of pairs of lead wires A42, 43gand 44, 45. As shown, each wire enters the tube end with its end bent radially outward through the tube wall thus to provide a terminal to which an lend of one core winding is attached. For retaining each pair of wires in the ends of tube 40, a resilient tube 46 of insulating, non-magneticV materialis inserted within a tube 40, with a'snug iit so that each wire is insulated from the other by the internal tube. Tube 40 may, if desired,A be formed of resilient material. With both tubes of resilient material and the outer tube of slightly less diameter than the bore diameter of the core but slightly larger than the. dimension between wires passing through the core on opposite sides thereof, the windings on the core are pressed against the core and held by the expanding pressure. of the tubes which thus function as positive retainers for both the core and the wires.

With reference to Figures 5 through 9vit will be seen that features of both previously described forms illustrative of the invention, may be combined in one unit identied by the numeral 49. That is,fthe resilient tubes ofthe modification shown in Figures 3 and 4 may be combined with rigid heads similar to those illustrated in Figures l and 2.

With reference to Figure 5 it will be understood that outer and inner tubesStl-,and 51 respectively are similar in construction bothas toshape and material as are tubes 40 and 46 of Figures 3 and 4, except as described below. Figure 7 illustrates how the telescoped resilient tubes assume the shape of bore 53 of core 54 and the wires 55 passing therethrough, thus to press against both in a manner holding the wrapped core firmly on the tube assembly.

Returning to Figure 5 it is seen that tubes -50 and 51 are provided with transyerseheads 56 and 57 of substantially rigid material either molded integrally therewith or formed separately and secured to thek tube ends in some suitable manner. Passing through and secured to heads 56 and `57 are lead wires SS through 61 which preferably are of the self supporting, easily bent type in common use on electrical components, such as resistors.

The. above described assembly, as shown in Figure 6, lends itself well to automatic assembly processes whereby the component is positioned over a printed circuit panel 62 with its leads extending parallel with its axis whereby automatic machinery can bend the leads toward the panel and into apertures 63 provided therefor and in which they are secured as by bending over the ends of the leads on the other side of the panel. A feature of this modification is that heads 56 and 57 may be so postioned relative to each other that leads 58 through 61 are aligned thus to facilitate such panel assembly.

Heads 56 and 57 are disk shape as shown in Figures 5,36.and 7but it is understood'that they may be formed in other suitable shapes, for example, such as those shown in Figures S and 9. Of course, where desirable, the whole assembly may be housed in a manner similar to those shown in Figures 1 4.

It will now be apparent that a magnetic core unit has been devised which is simple in construction and of few parts, all readily assembled as a compact assembly providing for attachmentto associated apparatus.

We claim:

l. A magnetic` core unit assembly comprising; aV magnetic toroidal core; a pair of windings on said core; a retainer of insulating material extending through the bore of said core, said retainer comprising a pair of similarly shaped planar T-shaped-insulating non-magnetic members each including a head and a bifurcated shank, said Shanks extending through the bore of said core from opposite sidesthereof with their planes angularly displaced and with said shanksinterlocked thereby to support said core between said heads; an open ended inner insulating non-magnetic tubular casing having an internal diameter substantially equal to the transverse dimension of said head and encircling said heads; an open ended outer casing having an inner diameter substantially the. same as the` outer diameter of said inner casing ywhereby the latter may be telescopically inserted within said outer casing; insulatingl non-magnetic means seated against said heads and the ends of said inner casing and sealing the ends of saidV outer casing;n and a pair of lead wires extendingthrough each of said sealing means with their inner ends turned through the adjacent retainer head and bonded to the ends of one of said windings, and with their outer ends exposed for connection to associated apparatus.

2. A magnetic core unit assembly comprising: a magnetic toroidal core; a pair of windings on said core; a retainer kof insulatingmaterial extending through the bore of said core, said retainer comprising a pair of similarly shaped planar` T-shaped insulating non-magnetic members each including a head and a bifurcated shank; said Shanks extending through the bore kof said core from opposite sides of said core with their planes angularly displaced and with said Shanks interlocked, thereby to support said core between said heads; an open ended inner insulating-non-magnetic tubular casing having an internal diameter substantially equal to the transverse diameter of said heads and extending from the top of one head to the top of therother; an open'ended outer casing having an innerl diametersubstantially the same` as the outer diameter of said `inner casing whereby the latter may be telescopically inserted in said outer casing; insulating nonmagnetic means seated against said heads andsaid inner casing and sealingvthe ends of said outer casing; and a pair` ofy lead wires extending through each of said sealing means with their inner ends turned through said'heads and bonded to the ends of one of said windings and their outer ends exposed for'connection to associated circuitry.

3. A magnetic core assembly comprising, a magnetic toroidal core, windings on said core, a retainer formed of two slidably intertting planar parts of insulating material extending through the bore of said core with their ends extending beyond the sides thereof, said retainer parts being similarly T-shaped, and said intertting parts f thereof comprising bifurcated legs which are inserted through the bore of said core respectively from opposite sides thereof andfrom different radial angles,V and means interlocking said intertting parts.

4. A construction according to claim 3 and including a tubular vhousing for said core and retainer, insulating means sealing the ends of said housing, and a pair of lead Wires extending through each of said sealing means with their inner ends attached to the adjacent end of said retainer ends and bonded to ends of said windings.

5. A magnetic core assembly accordingto claim 4,

wherein the tubular housing for` said core and retainer.

comprises a pair of telescoped tubular elements, the interior element of which is formed of insulating material and the outer element of which forms a metallic casing, and wherein the length of each retainer has a head portion of a dimension equal to the interior diameter of said insulating tubular element whereby said retainer is received snugly within said insulating element with the overall length of the retaining means being of substantially the same length as said insulating tubular element, and wherein said metallic tubular element extends beyond the ends of said insulating tubular element, and said insulating means sealing the ends of said housing are disk-like members having the same diameter as the interior diameter of said metallic housing and when inserted within said housing seat upon the ends of said insulating tubular element, thus to enclose the core assembly.

6. A magnetic core unit assembly comprising, a magnetic toroidal core, windings on said core, a core retainer formed by two slidably interfitting planar parts of insulating material extending through the bore of said core with their ends extending beyond the sides of the core,

each of said interitting parts including a slot forming bifureated legs by which they are interiitted with each other from diierent radial angles, and an inwardly extending portion on the ends of said bifurcated legs for engaging a complementary portion on the other of said planar parts and aligned with said slot on said part thereby to interlock said parts against undesired relative movement.

References Cited in the le of this patent UNITED STATES PATENTS 671,446 Lorscheider Apr. 9, 1901 1,657,001 Cragg Jan. 24, 1928 1,719,161 Aull July 2, 1929 1,741,265 Wappler Dec. 31, 1929 1,871,345 Rigante Aug. 9, 1932 2,290,680 Franz July 21, 1942 2,375,309 McCoy May 8, 1945 2,446,999 Camilli Aug. 17, 1948 2,823,362 Geroulo Feb. 1l, 1958 

